"The barriers from a premium publisher perspective are not really technological constraints. Naturally, sales channel conflict is a huge fear in the culture of a sales team. But even setting aside general fear, there are legitimate questions around price erosion and market liquidity. For most premium publishers, it seems the upside of using an exchange comes down to how much inventory is available for that channel. If 70% of impressions are unsold, there is a tremendous revenue upside that might even surpass the revenue from the direct channel. However, if the situation is reversed, where 80% of impressions or more are sold directly at top rates, then there is a huge risk exposure from direct sales price erosion. Likewise, liquidation could be a challenge if the supply is constrained one month and widely available the next. Regardless, a small test would go a long way to seeing if the perceived barriers had any credibility. Unfortunately, I don't think the questions surrounding price erosion and liquidity can be full tested on a small scale. So, even after testing, putting large volumes of inventory into the supply side exchange can be a bit of a leap of faith."